Evolutionary Fitness

We have not spent the last 65 million or so years finely honing our physiology to watch Oprah. Like it or not, we are the product of a very long process of adaptation to a harsh physical existence, and the past couple centuries of comparative ease and plenty are not enough time to change our genome. We humans are at our best when our existence mirrors, or at least simulates, the one we are still genetically adapted to live. And that is the purpose of exercise.

CrossFit kicks ass! It has a lot of overlap with economist turned exercise and diet pundit Art DeVany's "Evolutionary Fitness" ideas, which are also neat.
I've been doing it a few months, and I'm already a CrossFit addict. Short intense workouts - perfect for my busy schedule.
It's a sad thing that people think hours of boring cardio is the way to lose weight. Weight training and short, intense exercises get you way more bang for the buck. Shorter time and better results - what more can you ask for?

there's something I don't really get with evolutionnary fitness. If we reproduce exercises that indeed we have evolved to perform, doesn't that mean we will be able to do them very efficiently without shedding an ounce of precious precious fat ?

Our natural state is also determined by our 'natural' food supply. While our natural state is not to be fat, it might be to be lean while striving to be fat. In this case we might have evolved to avoid losing the little amount of fat we had while doing the exercises, thus the exercise would not promote fat loss.

That is right- and once we actually get our bodies to the point of being as lean and low in body fat as those of our ancestors were, we would not want to lose any of that precious unnoticeable fat or we would become emaciated! Instead our bodies would be finely honed machines that continue to increase in power, strength, and agility while remaining lean and muscular.

The point is to get our bodies into that state in which they perform at their best. Most of us are not even close to there yet. If we have evolved as hunter gatherers with a very high level of physical activity, yet we live as couch potatoes with a spare tire of belly fat, that belly fat will come flying off as soon as we begin to eat similarly to how our ancestors ate and exercise in a way that mimics much of our ancestors' physical activity.

The notion that our natural state is to be lean while striving to be fat is fine if we are eating lean protein (meat, fish, poultry), fresh vegetables, a little fruit, nuts, and seeds and also going through brief, intermittent periods of starvation. But it is not fine if we are eating refined carbohydrates and processed foods that did not exist in hunter gatherer times. This is why we must choose to avoid these fattening foods and stick to how our ancestors ate, adapting that to modern times.